Storage system and control method thereof

ABSTRACT

The plurality of host systems or the plurality of applications include an insertion unit for sending the identifier. The storage controller includes an analysis unit for identifying a host system or an application based on the identifier contained in the access information and analyzing an access pattern of access information sent from the identified host system or application, a management unit for managing the identifier, the analysis result of the access pattern analyzed with the analysis unit, and a control method for controlling the processing of data to be sent from a host system based on the analysis result or data to be stored in a logical volume, and a data processing controller for controlling the processing of data to be sent from a host system or data to be stored in a logical volume according to the control method managed by the management unit.

CROSS REFERENCES

This application relates to and claims priority from Japanese PatentApplication No. 2007-107261, filed on Apr. 16, 2007, the entiredisclosure of which is incorporated herein by reference.

BACKGROUND

The present invention generally relates to a storage system and itscontrol method, and in particular can be suitably applied to a storagesystem that controls a storage controller based on access informationfrom a host system.

Recently, in storage systems that handle vast amounts of data, a storagecontroller is used for controlling the input and output of data to andfrom the host system in order to store large-capacity data sent from thehost system.

A storage controller has a logical volume (hereinafter referred to as a“logical volume”) formed on a physical storage area provided by aplurality of hard disk devices configured to be operated according to aRAID (Redundant Array of Independent Inexpensive Disks) system.

The storage controller performs data processing according to the accesspattern information of a read/write request received from the hostsystem.

In relation to the above, disclosed is technology for improving theperformance of the overall storage system by increasing the processingspeed of data to be performed by the storage controller that receivedthe read/write request.

Japanese Patent Laid-Open Publication No. H10-240450 disclosestechnology of alleviating the deterioration in the system performance bystoring data of low access frequency in an internal storage apparatuseven when it is flushed from a cache memory when handling data of aplurality of access patterns in a single cache memory.

Japanese Patent Laid-Open Publication No. H11-212733 disclosestechnology of alleviating the deterioration in the system performance bya controller controlling a magnetic disk providing informationconcerning a logical volume to a storage controller, and allocating thecache memory to be prefetched by the storage controller to each logicalvolume.

Japanese Patent Laid-Open Publication No. 2003-131814 disclosestechnology of alleviating the deterioration in the system performance bya storage controller allocating its resources based on thecharacteristics of the access pattern from a host system.

Specification of Japanese Patent Application No. 2006-304526 describesthat it is possible to alleviate the deterioration in the systemperformance by calculating the performance load of a logical volumeaccording to the access pattern from a host system, and rearranging thetarget volume to be subject to performance load balancing to differentRAID groups.

SUMMARY

Since the foregoing conventional storage controllers merely perform dataprocessing according to the access pattern from a host system to alogical volume, there is a problem in that the performance of thestorage system would deteriorate depending on the particularity of theaccess pattern.

Further, the storage controller could not analyze the access patternfrom a host system to a logical volume and perform optimal control forthe relevant processing.

The present invention was made in view of the foregoing points, andproposes a storage system and its control method capable of improvingthe performance of a storage system even based on the particularity ofaccess patterns by analyzing the access pattern from a host system to alogical volume and performing optimal control.

In order to achieve the foregoing object, the present invention providesa storage system including a plurality of host systems or a plurality ofapplications for sending access information, and a storage controllerfor storing data in a logical volume provided in a storage area of aphysical disk. The plurality of host systems or the plurality ofapplications comprise an insertion unit for inserting an identifier thatidentifies respective host systems or respective applications into theaccess information and sending the identifier. The storage controllercomprises an analysis unit for identifying a host system or anapplication based on the identifier contained in the access informationand analyzing an access pattern of access information sent from theidentified host system or application; a management unit for managingthe identifier of the host system or the application, the analysisresult of the access pattern analyzed with the analysis unit, and acontrol method for controlling the processing of data to be sent from ahost system based on the analysis result or data to be stored in alogical volume; and a data processing controller for controlling theprocessing of data to be sent from a host system or data to be stored ina logical volume according to the control method managed by themanagement unit.

Thereby, the storage controller is able analyze the access pattern froma host system to a logical volume and perform optimal control for therelevant processing.

The present invention further provides a control method of a storagesystem including a plurality of host systems or a plurality ofapplications for sending access information, and a storage controllerfor storing data in a logical volume provided in a storage area of aphysical disk. The plurality of host systems or the plurality ofapplications comprise an insertion step for inserting an identifier thatidentifies respective host systems or respective applications into theaccess information and sending the identifier. The storage controllercomprises an analysis step for identifying a host system or anapplication based on the identifier contained in the access informationand analyzing an access pattern of access information sent from theidentified host system or application; a management step for managingthe identifier of the host system or the application, the analysisresult of the access pattern analyzed with the analysis unit, and acontrol method for controlling the processing of data to be sent from ahost system based on the analysis result or data to be stored in alogical volume; and a data processing control step for controlling theprocessing of data to be sent from a host system or data to be stored ina logical volume according to the control method managed at themanagement step.

Thereby, the storage controller is able analyze the access pattern froma host system to a logical volume and perform optimal control for therelevant processing.

According to the present invention, since the storage controller is ableanalyze the access pattern from a host system to a logical volume andperform optimal control for the relevant processing, it is possible toseek improvement in performance of the storage system even based on theparticularity of access patterns.

DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram showing the overall configuration of a storagesystem according to an embodiment of the present invention;

FIG. 2 is a chart showing a pattern result table according to anembodiment of the present invention;

FIG. 3 is a chart showing a usage table according to an embodiment ofthe present invention;

FIG. 4 is a chart showing an LU management table according to anembodiment of the present invention;

FIG. 5 is a flowchart showing pattern analysis processing according toan embodiment of the present invention;

FIG. 6 is a flowchart showing control processing according to anembodiment of the present invention;

FIG. 7 is a flowchart showing control processing according to anembodiment of the present invention;

FIG. 8 is a flowchart showing creation processing of a new logicalvolume according to an embodiment of the present invention;

FIG. 9 is a flowchart showing creation processing of a new logicalvolume according to an embodiment of the present invention;

FIG. 10 is a flowchart showing a part of the pattern analysis processingaccording to an embodiment of the present invention;

FIG. 11 is a flowchart showing a part of the control processingaccording to an embodiment of the present invention;

FIG. 12 is a conceptual diagram showing the order of destaging accordingto an embodiment of the present invention;

FIG. 13 is a conceptual diagram explaining boundary adjustment accordingto an embodiment of the present invention;

FIG. 14 is a flowchart showing a part of the pattern analysis processingaccording to an embodiment of the present invention;

FIG. 15 is a flowchart showing a part of the creation processing of anew logical volume according to an embodiment of the present invention;

FIG. 16 is a flowchart showing a part of the pattern analysis processingupon receiving a sequence write request according to an embodiment ofthe present invention;

FIG. 17 is a flowchart showing a part of the control processing uponreceiving a sequence write request according to an embodiment of thepresent invention;

FIG. 18 is a flowchart showing a part of the pattern analysis processingupon receiving a sequence read request according to an embodiment of thepresent invention;

FIG. 19 is a flowchart showing a part of the control processingaccording to an embodiment of the present invention;

FIG. 20 is a list of control methods according to an embodiment of thepresent invention; and

FIG. 21 is a block diagram showing the overall configuration of astorage system according to a second embodiment of the presentinvention.

DETAILED DESCRIPTION

An embodiment of the present invention is now explained in detail withreference to the attached drawings.

(1) Configuration of Storage System in First Embodiment

Foremost, the storage system according to the first embodiment isexplained below.

FIG. 1 shows an overall storage system 1 according to an embodiment ofthe present invention. The storage system 1 is configured by a hostsystem 2 connected to a storage apparatus 4 via a network 3, the storageapparatus 4 being connected to a management terminal 12, and themanagement terminal 12 being connected to a support system 14 via anetwork 13.

The host system 2 is a computer device comprising information processingresources such as a CPU (Central Processing Unit) and a memory, andcomprises an information input device (not shown) such as a keyboard, aswitch, a pointing device, or a microphone and an information outputdevice (not shown) such as a monitor display or a speaker. The hostsystem 2 comprises an application 20 having various types of applicationsoftware A to C, and a driver 21.

The driver 21 is software for achieving the present invention, andincludes an identifier addition program 22 and a data length changeprogram 23.

The identifier addition program 22 is a program for adding, upon sendingdata from a host system to the storage apparatus 4, an identifier todata for causing the storage apparatus 4 to identify such data.

The data length change program 23 is a program for changing the datatransfer length of data sent from the storage apparatus 4.

Incidentally, the host system 2 contains an OS (Operating System) or afile system for managing files.

Networks 3, 13, for example, are configured from a SAN (Storage AreaNetwork), a LAN (Local Area Network), Internet, a public line or adedicated line. Communication between the host system 2 and the storageapparatus 4 via the network 3 is conducted, for instance, according to afibre channel protocol when the network 3 is a SAN, and according to aTCP/IP (Transmission Control Protocol/Internet Protocol) protocol whenthe network 13 is a LAN.

The storage apparatus 4 is a storage controller comprising a controller5 for controlling the input and output of data to and from the hostsystem 2, and a hard disk drive unit 11 for storing data from the hostsystem 2.

The controller 5 is configured by a channel adapter 6, a shared memory7, a cache memory 9, and a disk adapter 10 being connected via aconnection unit 8. The transfer of data and commands among the channeladapter 6, the shared memory 7, the cache memory 9, and the disk adapter10 is conducted by a switch such as an ultra-fast crossbar switch forperforming data transfer with high-speed switching, or a bus.

The channel adapter 6 is configured as a microcomputer-system comprisinga microprocessor, a local memory, a communication interface (not shown)and the like, and comprises ports (not shown) for connection to thenetwork 3. The channel adapters 5A, 5B interpret various commands sentfrom the host system 2 and execute necessary processing. The ports ofthe channel adapter 6 are allocated with a network address (forinstance, an IP address or a WWN) for identifying the respective ports,and each channel adapter 6 is thereby able to individually function as aNAS (Network Attached Storage).

The shared memory 7 is a storage memory to be shared by the channeladapter 6 and the disk adapter 10. The shared memory 7 is primarily usedfor storing system configuration information and various controlprograms read from a system volume when the power of the storageapparatus 4 is turned on, and commands from the host system 2.

The cache memory 9 is also a storage memory to be shared by the channeladapter 6 and the disk adapter 10. The cache memory 9 is primarily usedfor temporarily storing user data to be input and output to and from thestorage apparatus 4.

The cache memory 9 stores a pattern analysis program 90 for analyzing aplurality of different access patterns, a pattern result table 91 forregistering results based on the pattern analysis program 90, aperformance monitoring program 92 for monitoring the performance speedof the overall storage system 1, a usage table 93 for managing the usageof a logical volume, an LU management table 94 for managing the logicalvolume formed with the hard disk drive unit 11, a control program 95 forperforming control processing based on the pattern analysis results, anda volume creation program 96 for creating a new logical volume withparameters after the control. The pattern result table 91, the usagetable 93 and the LU management table 94 will be described later.

The disk adapter 10 is configured as a microcomputer system comprising amicroprocessor, a memory and the like, and functions as an interface forperforming protocol control during communication with the hard diskdrive unit 11. The disk adapter 10, for instance, is connected to thehard disk drive unit 11 via a fibre channel cable, and sends andreceives data to and from the hard disk drive unit 11 according to thefibre channel protocol.

The hard disk drive unit 11, for example, is configured from a pluralityof hard disk drives 110 formed of expensive hard disk drives 110 such asSCSI (Small Computer System Interface) disks or inexpensive hard diskdrives such as SATA (Serial AT Attachment) disks.

One or more logical volumes LU are defined in a storage area provided bythe hard disk drives 110. Data from the host system 2 is read from andwritten into the logical volumes LU in block units of a prescribed size.

Each logical volume LU is allocated with a unique identifier (LUN:Logical Unit Number). In the case of this embodiment, the input andoutput of user data are performed by combining the identifier and aunique number (LBA: Logical Block Address) to be allocated to therespective blocks as an address, and designating this address.

The management terminal 12 is a computer device for a server to beoperated for managing the storage apparatus 4, and, for instance, isconfigured from a laptop personal computer. The management terminal 12is able to monitor the occurrence of a failure in the storage apparatus4 and display such failure on a display screen (not shown).

The support system 14 is a computer system to be operated by monitoredfor the maintenance of the storage apparatus 4. In the support system14, information concerning the storage apparatus 4 is sent from themanagement terminal 12 managing the storage apparatus 4.

(2) Tables

(2-1) Pattern Result Table

The pattern result table 91 stored in the cache memory 9 is nowexplained.

The pattern result table 91 is a table for storing and managing theanalysis result of a plurality of different access patterns sent fromthe host system 2. As shown in FIG. 2, the pattern result table 91 isconfigured from a “pattern number” field 91A, a “logical volume number”field 91B, a “host system number” field 91C, an “application” field 91D,a “usage” field 91E, a “performance threshold value” field 91F, a “typeof I/O” field 91G, a “cycle” field 91H, a “boundary” field 91I and a“control method” field 91J.

The “pattern number” field 91A stores the number given to an analyzedpattern after the plurality of different access patterns sent from thehost system 2 are analyzed.

The “logical volume number” field 91 stores the number of a logicalvolume LU storing data based on the analyzed access pattern.

The “host system number” field 91C stores the number of the host system2 that sent the access pattern to the storage apparatus 4.

The “application” field 91D stores the type of application loaded in thehost system as the source of access information.

The “usage” field 91E stores the usage of the logical volume LU. As theusage, there are a usage for databases and a usage for archives. Thedetails will be described later.

The “performance threshold value” field 91F stores the threshold valueof the performance of the corresponding logical volume LU. Thisthreshold value is to be set by the user. When the user does not inputany value, “0” is set.

The “type of I/O” field 91G stores the type of access pattern from thehost system 2 to the logical volume LU.

The type of access pattern can be broadly classified as a random accessor a sequential access. Random access refers to the I/O load where thecontinuously issued read or write request does not show the adjacentdata. Random access refers to any and all so-called I/O loads that arenot generally sequential regardless of whether or not the distributionof data arrangement is truly random. Random access is characteristic tointensive applications of an I/O request. There are two types of randomaccess; namely, random write and random read.

Sequential access refers to the I/O load of the continuous read or writerequest of adjacent data. Sequential access is characteristic toapplications that transfer large data. There are two types of sequentialaccess; namely, sequential read and sequential write.

The “cycle” field 91H stores one cycle of the read/write request to berecognized by the storage apparatus 4.

The “boundary” field 91I stores the displacement value of the startlocation of data to be written in the logical volume LU.

The “control method” field 91J stores the control method to be performedby the storage apparatus based on the analyzed access pattern.

(2-2) Usage Table

Information stored in the “usage” field 91E is now explained withreference to the usage table 93 shown in FIG. 3.

As information to be stored in the “usage” field 91E, there is “table,”“index,” “journal” and “log” information to become information fordatabases, and “archive” information to become information for archives.

When storing “table” information and “index” information in the “usage”field 91E, such information is selected on the assumption that therandom read access is an operation to be primarily performed to thelogical volume LU in advance by the storage apparatus 4.

When storing “journal” information and “log” information in the “usage”field 91E, such information is selected on the assumption that thesequential write access is an operation to be primarily performed to thelogical volume LU in advance by the storage apparatus 4. Incidentally, ajournal is data for storing the update history of data to be stored inthe logical volume LU.

When storing “archive” information in the “usage” field 91E, suchinformation is selected on the assumption that the sequential readaccess is an operation to be primarily performed to the logical volumeLU in advance by the storage apparatus 4.

(2-3) LU Management Table

As shown in FIG. 4, the LU management table 94 is a table for managingthe logical volumes LU formed in the storage apparatus 4. The LUmanagement table 94 is configured from a “logical volume number” field94A, an “alias” field 94B, a “host system number” field 94C, and a“capacity” field 94D.

The “logical volume number” field 94A stores the number given to thelogical volume LU.

The “alias” field 94B stores the alias of the logical volume LU. Forexample, when the logical volume LU is “1,” this shows that it is alogical volume for storing the store master data.

The “host system number” field 94C stores the number of the host system2 that will access a certain logical volume LU.

The “capacity” field 94D stores capacity information currently used bythe logical volume LU.

(3) Pattern Analysis Function and Control Function

This storage system 1 is characterized in that, by including anidentifier in the access information from the host system 2 to thestorage apparatus 4 and the storage apparatus 4 analyzing the accesspattern based on the access information (pattern analysis function) andperforming optimal control based on the analysis result (controlfunction), the storage apparatus 4 is able to make access while beingconscious of the access pattern.

Here, access information refers to the read/write request from the hostsystem 2.

The method of realizing the characteristic points of the presentinvention is now explained.

Foremost, although there are a plurality of access patterns, thefollowing explanation will be based on pattern analysis processing andcontrol processing corresponding to all access patterns. Patternanalysis processing and control processing based on individual andspecific access patterns will be described later.

(3-1) Pattern Analysis Processing

Foremost, pattern analysis processing where the storage apparatus 4analyzes some type of access pattern based on the access informationfrom the host system 2 is explained. Pattern analysis processing isexecuted by the channel adapter 6 of the storage apparatus 4 based onthe pattern analysis program 90.

As shown in FIG. 5, pattern analysis processing is started when the hostsystem 2 sends data to the storage apparatus 4 (S0, S1).

The host system 2 inserts an identifier into the access information tobe sent to the storage apparatus 4 (S2). For example, the host system 2inserts an identifier using an empty bit of SCSI. Here, an identifier isa host computer identifier or an application identifier, and, forinstance, the host system number or the type of application is insertedusing an empty bit of SCSI into the access information to be sent.Incidentally, in this embodiment, although a host computer identifierand an application identifier are inserted as the identifier into theaccess information, only one between the host computer identifier andthe application identifier can also be inserted.

When the host system 2 inserts the identifier into the accessinformation to be sent, it sends data to the storage apparatus 4 (S3),and the processing is ended on the side of the host system 2 (S8).

When the storage apparatus 4 receives the access information from thehost system 2 (S4), it determines the access information, and analyzesand determines the access pattern of the determined access information(S5).

Subsequently, the storage apparatus 4 inputs the identifier, and theanalysis result of the access information and access pattern into thepattern result table 91 (S6). For example, the storage apparatus 4receives a prescribed access pattern from the host system 2, and inputsthe analyzed result as pattern “1.” The other access patterns from thehost system 2 that do not correspond to pattern “1” are input as pattern“2” and pattern “3.”

When the storage apparatus 4 finishes its input into the pattern resulttable 91, the processing is ended on the side of the storage apparatus 4(S9).

Further, at step S4, when the storage apparatus 4 receives the accessinformation (S4), it performs normal data processing according to theaccess information from the host system 2 (S7). Processing is performedin parallel to steps S5 and S7.

For example, when the access information is a write request, the storageapparatus 4 temporarily stores the sent data, subsequent to the accessinformation, in the cache memory 9, and performs destaging toward thelogical volume LU designated by the access information.

When the access information is a read request, the storage apparatus 4reads the data requested by the host system 2 from the logical volume LUstoring such data, and sends it to the host system 2.

When the normal processing is complete, the storage apparatus 4 ends thepattern analysis processing (S9).

(3-2) Control Processing

Control processing to be performed by the storage apparatus 4 after theanalysis result of each pattern is registered in the pattern resulttable 91 as a result of the storage apparatus 4 receiving accessinformation containing the identifier from the host system 2 severaltimes. Control processing is the process of performing control on theside of the storage apparatus 4 while being conscious of theapplications loaded in the host system 2.

Control processing is primarily executed by the channel adapter 6 of thestorage apparatus 4 based on the control program 95.

Foremost, as shown in FIG. 6 and FIG. 7, control processing is startedwhen the host system 2 sends data to the storage apparatus 4 (S20, S21).

The host system 2 inserts an identifier into the access information tobe sent to the storage apparatus 4 (S22). Similar to the patternanalysis processing, the host system 2 inserts an identifier into theaccess information using an empty bit of SCSI. Here, an identifier is ahost computer identifier and an application identifier, and, forexample, the host system number and the type of application areinserted.

When the host system 2 inserts an identifier into the access informationto be sent, it sends the access information to the storage apparatus 4(S23), and ends the processing (S34).

When the storage apparatus 4 receives the access information from thehost system 2 (S24), it confirms the identifier contained in thereceived access information (S25).

The storage apparatus 4 refers to the pattern result table 91, anddetermines whether the identifier contained in the access informationcorresponds to the existing access pattern registered in the patterntable result table 91 (S26).

When the storage apparatus 4 determines that the access information fromthe host system 2 is an existing access pattern registered in thepattern table result table 91 (S26: YES), it determines whether thecontrol method of the sent access information has been input in the“control method” field 91J of the pattern result table 91 (S27).

When the storage apparatus 4 determines that the control method of thesent access information has not been input in any way into the “controlmethod” field 91J (S27: NO), the storage apparatus 4 determines thecontrol method of the sent access information (S28), and performscontrol processing based on the determined control method (S29).

Subsequently, the storage apparatus 4 activates the performancemonitoring program 92, detects the processing speed of the storagesystem 1 (S30), and determines whether the processing speed of thestorage system 1 improved (S31).

When the storage apparatus 4 determines that the processing speed of thestorage system 1 improved as a result of performing the controlprocessing (S31: YES), it registers the control method determined atstep S28 in the “control method” field 91J of the pattern result table91 (S32), and ends this processing (S35).

At step S27, when the storage apparatus 4 determines that the controlmethod of the send access information has been input into the “controlmethod” field 91J registering the identifier of the sent data (S27:YES), it performs control processing according to the contents describedin the “control method” field 91J (S33), and then ends this processing(S35).

At step S26, when the storage apparatus 4 determines that the accessinformation from the host system 2 is not an existing access patternregistered in the pattern table result table 91 (S26: NO), itre-activates the pattern analysis program 90.

After activating the pattern analysis program 90, the storage apparatus4 performs normal processing according to the access informationreceived from the host system 2 (S7), and thereafter ends the processing(S9). Further, the storage apparatus 4 analyzes and determines theaccess information (S5), registers the analysis result in the patternresult table 91 (S6), and thereafter ends the processing (S9).

Incidentally, at step S31, when the storage apparatus 4 determines thatthe processing speed of the storage system 1 did not improve (S31: NO),it ends this processing (S35).

(3-3) Logical Volume Creation Processing

Upon performing pattern analysis processing or control processing,depending on the storage environment, performance of the storage system1 may improve by creating a new logical volume LU with the controlledparameter. Here, processing of the storage apparatus 4 creating a newlogical volume LU in the foregoing case is explained. Logical volumecreation processing is primarily executed by the channel adapter 6 ofthe storage apparatus 4 based on the volume creation program 96.

Foremost, as shown in FIG. 8 and FIG. 9, the storage apparatus 4 sends amessage to the effect of creating a new logical volume LU to themanagement terminal 12, and the logical volume creation processing isstarted when the management terminal 12 receives the message (S40, S41).

Subsequently, the management terminal 12 sends a creation command to thestorage apparatus 4 to create a logical volume LU (S42).

When the storage apparatus 4 receives the logical volume creationcommand (S43), it sends the LU management table 94 to the managementterminal 12 (S44).

When the management terminal 12 receives the LU management table 94, itdisplays a list of the existing logical volumes LU on a screen of themanagement terminal 12 (S45).

The management terminal 12 determines whether an existing logical volumeLU with the same parameter as the new logical volume LU to be created isin the LU management table 94 (S46).

When the management terminal 12 determines that an existing logicalvolume LU with the same parameter as the new logical volume LU to becreated is not in the LU management table 94, or that there is anexisting logical volume LU but is not to be selected (S46: NO), itinputs the parameter and creates the new logical volume LU (S47).

Here, a parameter, for example, is the number of the host system 2 orthe type of applications A to C. The usage of the logical volume LU isarbitrarily selected from a list in the usage table 93 shown in FIG. 3.Further, as the parameter, the user may also arbitrarily input theperformance threshold value.

When the management terminal 12 inputs the parameter, it sends thisparameter to the storage apparatus 4 (S48), and ends the logical volumecreation processing (S56).

Meanwhile, the storage apparatus 4 that received the parameterdetermines whether a logical volume LU with the same characteristics asthis parameter exists in the pattern result table 91 (S49).

When the storage apparatus 4 determines that a logical volume LU withthe same characteristics as this parameter exists in the pattern resulttable 91 (S49: YES), it refers to the corresponding logical volume LUinformation of the pattern result table 91, and creates a logical volumeLU based on the logical volume information (S50).

When the storage apparatus 4 registers the number of the created newlogical volume LU and the referred logical volume information in thepattern result table 91 (S51), it ends this logical volume creationprocessing (S57).

Meanwhile, at step S49, when the storage apparatus 4 determines that alogical volume LU with the same characteristics as this parameter doesnot exist in the pattern result table 91 (S49: NO), it creates a logicalvolume LU, registers the number and parameter of the created new logicalvolume LU in the pattern result table 91 (S52), and ends this logicalvolume creation processing (S57).

At step S46, when the management terminal 12 determines that an existinglogical volume LU with the same parameter as the new logical volume LUto be created is in the LU management table 94 (S46: YES), it performsthe processing at steps S53 to S55 as with the processing at steps S50,S51 and S57 according to the same processing routine.

(3-4) Processing Based on Specific Access Pattern

Pattern analysis processing and control processing to be specificallyperformed by the storage apparatus 4 based on specific access patternsare now explained.

(3-4-1) Mixed Access Pattern of Write-Read-Write

Foremost, as access pattern 1, a case is explained where the storageapparatus 4 receives a read/write request from the host system 2 inwhich write-read-write is one cycle.

The storage environment before performing control in this embodiment wasas follows.

In other words, when the storage apparatus 4 receives the initial writeaccess request, data from the host system 2 is foremost written in thecache memory 9. Here, the write time was approximately 0.1 (ms).

Subsequently, data temporarily written in the cache memory 9 is destagedto the hard disk drive 110. Destaging is performed each time data iswritten in the cache memory 9. While destaging is performed, the cachememory 9 is locked so that the other areas in the cache memory 9 cannotbe accessed. Here, the destaging time was approximately 10 (ms).

Subsequently, when the storage apparatus 4 receives the read accessrequest, data written in the hard disk drive 110 is read after the cachememory 9 is unlocked. Here, the read time was approximately 0.1 (ms).

The cache memory 9 thereafter receives a write access request foroverwriting the data. The overwrite data from the host system 2 iswritten in the cache memory 9. Here, the write time was approximately0.1 (ms).

Thereby, under the storage environment before performing control, whenthe storage apparatus 4 receives a read/write request in whichwrite-read-write is one cycle, it took approximately 10.3 (ms) toperform all processing.

Thus, the foregoing pattern analysis processing and control processingare specifically applied to establish the post-control storageenvironment.

FIG. 10 is a flowchart showing a part of the pattern analysisprocessing.

Foremost, the host system 2 and the storage apparatus 4 execute steps S0to S4 explained with reference to FIG. 5.

Subsequently, since the data sent from the host system 2 contains anidentifier, the storage apparatus 4 detects and determines the accesscycle to a single logical volume (S5A). Specifically, the storageapparatus 4 determines that the access cycle to the logical volume LU isone cycle of write-read-write.

When the analysis and determination of the pattern are complete, thestorage apparatus 4 inputs “write-read-write is one cycle” in the“cycle” field 91H of the pattern result table 91 (S6A). The storageapparatus 4 thereafter ends the pattern analysis processing (S9).

FIG. 11 is a flowchart showing a part of the control processing.

The host system 2 and the storage apparatus 4 execute steps S20 to S27explained with reference to FIG. 6 and FIG. 7.

When the storage apparatus 4 determines that the control method has notyet been input in the “control” field 91J of the pattern result table 91(S27: NO), it sets “write-read-write” as one cycle, processes one-cycleworth of read/write request, and thereafter destages the datatemporarily stored in the cache memory 9 to the hard disk drive 110 soas to determine the control method (S28A).

The storage apparatus 4, based on this determination result, processesone-cycle worth of read/write request and thereafter performs destagingto the hard disk drive 110 (S29A).

Subsequently, the storage apparatus 4 activates the performancemonitoring program 92 and detects the processing speed of the storagesystem 1 (S30A), and determines whether the processing speed of thestorage system 1 improved (S31A).

When the storage apparatus 4 determines that the processing speed of thestorage system 1 improved (S31: YES), it registers the control method of“perform destaging after completion of one cycle” in the “control” field91J of the pattern result table 91 (S32A), and then ends this processing(S35).

Thereby, the order of destaging data from the cache memory 9 to the harddisk drive 110 upon receiving the read/write request from the hostsystem 2 will be the order shown in FIG. 12.

As a result of the storage apparatus 4 analyzing the mixed accesspattern of write-read-write, it is able to recognize the read/writerequest of write-read-write as one cycle. Thus, it is possible to omitthe destaging time of data performed during the read/write request thatwas required by the storage apparatus 4 before performing control.

Further, under a consolidation environment, since the environment issuch that one storage apparatus 4 connects a plurality of host systems 2or a plurality of types of applications, there are cases where varioustypes of access coexist. In such a case, the storage apparatus 4 is ableto distinguish the read/write request within one cycle by confirming theidentifier inserted into the access information.

As a further specific example, even in a case when one host system 2 orapplication is using one logical volume LU, or in a case when aplurality of host systems 2 or applications are using one logical volumeLU, it will suffice so as long as the applications coordinate and forman access pattern to one logical volume LU.

(3-4-2) Boundary Adjustment in Access Pattern

Subsequently, as access pattern 2, a case is explained where the storageapparatus 4 receives a read/write request, which is sequential read orwrite or random read or write, from the host system 2 is explained.Here, for the sake of convenience, an example where the storageapparatus 4 receives a read/write request that is sequential write isexplained.

Although this embodiment can be applied regardless of the RAID level,here, as shown in FIG. 13, a case is explained where two hard diskdrives 110 (indicated as HDD 1 and HDD 2 in FIG. 13) are configured asRAID 0 striping.

Specifically, the hard disk drive 110 of a striping configurationexplained here is a case where the storage area (stripe ST) of storing asingle data transfer length to be written from the cache memory 9 to thehard disk drive 110 is 64 KB, and the data transfer length (segment SG)from the host system 2 is 16 KB. During the writing into the hard diskdrive 110, the four segments in the cache memory 9 are collectivelywritten.

The storage environment before performing control was as follows.

Since the host system 2 uses the first several KB of data in orderprocess data in a specific OS or application, the write start locationin the cache memory 9 will be written upon being displaced several KB.This displacement is referred to as a boundary P.

For example, if the boundary P is 0.5 KB, since the single data transferlength written in the cache memory 9 is 16 KB, the write start locationwill start from 0.5 KB and the write end location will become 16.5 KB.

Here, since two segments are locked, it is necessary to wait for thewriting in the hard disk drive 110 according to the subsequentread/write request.

Due to this standby time, the efficiency of the hard disk drive 110 willdeteriorate. Similarly, even when the segments of the cache memory 9 arecollectively written in the hard disk drive 110, a boundary P willsimilarly arise, and, although writing should only be made essentiallyin the hard disk drive HDD 1, writing will be made in both the hard diskdrives HDD 1, HDD 2.

Thus, by specifically applying the foregoing pattern analysis processingand control processing, the post-control storage environment isestablished.

Foremost, under the test environment of the storage system 1, the hostsystem 2 and the storage apparatus 4 execute the pattern analysisprocessing. Here, under the test environment, a case is explained wherea read/write request to a certain logical volume LU is received.

FIG. 14 is a flowchart showing a part of the pattern analysisprocessing.

Foremost, the host system 2 and the storage apparatus 4 execute steps S0to S4 explained with reference to FIG. 5.

Since an identifier is contained in all access information sent from thehost system 2, the storage apparatus 4 measures the boundary P of thestart LBA and takes statistics of the boundary P (S5B). The storageapparatus 4 thereafter analyzes and determines the status of theboundary P and the size of the boundary P (S5B). Specifically, thestorage apparatus 4, for example, determines that there is a boundary P,and that the boundary P is 0.5 KB.

When the analysis and determination of the pattern is complete, thestorage apparatus 4 inputs “there is boundary, and that boundary is 0.5KB” in the “boundary” field 91I of the pattern result table 91 (S6B).

In a specific example of this embodiment, since there is a boundary P,the storage apparatus 4 sends a message to the effect of “optimizationof performance by using another logical volume LU is recommended” to themanagement terminal 12 (S6B).

Incidentally, when there is no boundary P, the storage apparatus 4inputs that the boundary P is “0” in the pattern result table 91.

The storage apparatus 4 thereafter ends this pattern analysis processing(S9).

FIG. 15 is a flowchart showing a part of the logical volume creationprocessing.

At step S6B, when the storage apparatus 4 sends a message to themanagement terminal 12, the storage apparatus 4 and the managementterminal 12 execute processing from step S40 to step S44.

When the management terminal 12 receives an LU management table 94 fromthe storage apparatus 4, it displays a list of the existing logicalvolumes LU on a screen of the management terminal 12 (S45B).

In addition, the management terminal 12 selects the logical volume LUused under the test environment from the list of the existing logicalvolumes LU (S45B).

The management terminal 12 determines whether an existing logical volumeLU with the same parameter as the new logical volume LU to be createdexists in the LU management table 94 (S46B).

Since the management terminal 12 selected the existing logical volumeused under the test environment at step S45B, it determines that thereis an existing logical volume (S46B: YES).

The storage apparatus 4 refers to the “boundary” field 91I of thepattern result table 91, and creates a logical volume LU in which thestart LBA is matched to the boundary (S53B). According to the specificexample of this embodiment, since it is determined that the boundary atstep S6B is 0.5 KB, a logical volume LU in which the start LBA isdisplaced 0.5 KB is created. In other words, the start LBA, as shown inFIG. 13, will become 15.5 KB or −0.5 KB.

Subsequently, as explained in FIG. 8, the storage apparatus 4 registersthe number of the created new logical volume LU in the pattern resulttable 91 (S54). In addition, the storage apparatus 4 registers theaddress as the logical volume information, from which boundary P wasdeducted, as the boundary value in the pattern result table 91 (S54),and then ends this logical volume creation processing (S55).

A specific example of this embodiment can also be realized by using AOU(Allocation on Use) volume of providing a virtual logical volume to thehost system 2 without creating a logical volume LU of a fixed capacityfrom the hard disk drive 110, and dynamically allocating the storagearea of the hard disk drive 110 to the virtual logical volume accordingto the request from the host system 2.

Further, when there is a read/write request from the host system 2 tothe AOU volume, the storage apparatus 4 can delete the target AOU volumeaccording to the request from the host system 2.

Specifically, the host system 2 has applications A to C for executingbusiness operations, and an OS or a file system for managing the storagearea of the AOU volume to be used by the applications A to C.

The OS or the file system has a file stored in the storage area of theAOU volume, and a management table for managing the address storing thefile.

When the OS or the file system receives a file read request from theapplications A to C, it sends the address storing the file that receivedthe read request from the management table to the storage apparatus 4together with the read request.

Similarly, when the OS or the file system receives a file write requestfrom the applications A to C, it sends the address of an empty area fromthe management table and the data and write request of the file to thestorage apparatus 4.

When a physical storage area is not allocated to the correspondingaddress, the controller 5 of the storage apparatus 4 that received theread/write request allocates a physical storage area, and stores thedata from the host system 2 in the allocated physical area.

Further, when the OS or the file system receives a deletion (delete)request from the applications A to C, it deletes the file to be deletedfrom the management table. Further, the OS or the file system sends theaddress of the deleted file to the storage apparatus 4 together with thedeletion request.

When the controller 5 of the storage apparatus 4 receives the deletionrequest, it releases the physical storage area corresponding to thisaddress.

Thereby, since the storage apparatus 4 will be able to analyze theaccess pattern and detect the boundary, and create a new logical volumeLU while giving consideration to the boundary in advance, it is possibleto avoid the deterioration in the efficiency of the hard disk drive 110.

Further, by setting the deletion request to be access information, asystem configuration is realized where the OS or the file system is ableto send the deletion request, and receive the deletion request on theside of the storage apparatus.

(3-4-3) Sequential Access

Subsequently, as access pattern 2, a case where the storage apparatus 4receives a read/write request that is sequential read or write isexplained.

(3-4-3-1) Sequential Write

Here, a case where the storage apparatus 4 receives a sequential writerequest is taken as an example and explained.

Foremost, the storage environment before performing control was asfollows.

If the storage apparatus 4 simultaneously receives access information,which is a sequential write request, from the host system 2A and thehost system 2B, since the reception of both host systems 2 will berecognized simultaneously, it appeared to be the reception of a randomwrite request.

Thus, by specifically applying the pattern analysis processing and thecontrol processing, the post-control storage environment will beestablished.

FIG. 16 is a flowchart showing a part of the pattern analysisprocessing.

Foremost, the host system 2 and the storage apparatus 4 execute steps S0to S4 explained with reference to FIG. 5.

Since an identifier is contained in all access information sent from thehost system 2, the storage apparatus 4 detects and determines the typeof read/write request (S5C). Specifically, the storage apparatus 4determines that the type of I/O is sequential write from the identifier.

When the analysis and determination of the pattern are complete, thestorage apparatus 4 inputs that the pattern is “sequential write” in the“type of I/O” field 91H of the pattern result table 91 (S6C). Thestorage apparatus 4 thereafter ends the pattern analysis processing(S9).

FIG. 17 is a flowchart showing a part of the control processing.

The host system 2 and the storage apparatus 4 execute steps S20 to S27.

When the storage apparatus 4 determines that nothing has been input intothe “control” field 91J of the pattern result table 91 (S27: NO), itdetermines the control method in a case of receiving “sequential write”(S28C).

Specifically, the storage apparatus 4 determines a control method ofaccumulating data received from the respective host systems 2 indifferent storage areas in the cache memory 9, and collectively writingthe same in the hard disk drive 110.

The storage apparatus 4, based on this determination result,collectively writes the accumulated data in the hard disk drive 110(S29C).

The storage apparatus 4 thereafter activates the performance monitoringprogram 92, detects the processing speed of the storage system 1 (S30C),and determines whether the processing speed of the storage system 1improved (S31C).

When the storage apparatus 4 determines that the processing speed of thestorage system 1 improved (S31C: YES), it registers the control methodof “collective writing in hard disk drive 110” in the “control” field91J of the pattern result table 91 (S32C), and then ends this processing(S35).

(3-4-3-2) Sequential Read

Subsequently, a case where the storage apparatus 4 receives accessinformation, which is a sequential read request, is taken as an exampleand explained.

Similar to the case of receiving a sequential write request, in thestorage environment before performing control, if the storage apparatus4 simultaneously receives a sequential read request from the host system2A and the host system 2B, since the reception of both host systems 2will be recognized simultaneously, it appeared to be the reception of arandom write request.

FIG. 18 is a flowchart showing a part of the pattern analysisprocessing.

Foremost, the host system 2 and the storage apparatus 4 execute steps S0to S4 explained with reference to FIG. 5.

Since an identifier is contained in all access information sent from thehost system 2, the storage apparatus 4 detects and determines the typeof read/write request (S5D). Specifically, the storage apparatus 4determines that the type of I/O is access information of a sequentialread request from the identifier.

When the analysis and determination of the pattern are complete, thestorage apparatus 4 inputs that the pattern is “sequential read” in the“type of I/O” field 91H of the pattern result table 91 (S6D). Thestorage apparatus 4 thereafter ends the pattern analysis processing(S9).

FIG. 19 is a flowchart showing a part of the control processing.

The host system 2 and the storage apparatus 4 execute steps S20 to S27.

When the storage apparatus 4 determines that nothing has been input intothe “control” field 91J of the pattern result table 91 (S27: NO), itdetermines the control method in a case of receiving “sequential read”(S28D).

Specifically, the storage apparatus 4 determines a control method ofprefetching necessary data to be sent to the respective host systems 2from the hard disk drive 110 to the cache memory 9.

The storage apparatus 4, based on the foregoing determination result,prefetches the necessary data from the hard disk drive 110 and stores itin the cache memory 9 (S29D).

The storage apparatus 4 thereafter activates the performance monitoringprogram 92, detects the processing speed of the storage system 1 (S30D),and determines whether the processing speed of the storage system 1improved (S31D).

When the storage apparatus 4 determines that the processing speed of thestorage system 1 improved (S31D: YES), it registers the control methodof “prefetching in cache memory 9” in the “control” field 91J of thepattern result table 91 (S32D), and then ends this processing (S35).

As described above, due to the identifier inserted into the accessinformation, the storage apparatus 4 is able to analyze and control theaccess pattern to create a storage environment that matches theenvironment on the host system side to which the inserted identifier isto be sent host system.

FIG. 20 shows the matters that can be controlled by the storageapparatus 4 depending on the type of read/write request.

When the type of read/write request is sequential read, as describedabove, a control method is executed where the storage apparatus 4predicts data to be prefetched from the hard disk drive 110 to the cachememory 9, and thereby optimizes the process. In addition, during thepattern analysis processing, a control method is executed where thestorage apparatus 4 optimizes the prefetch amount during the control bycomprehending the volume of data to be prefetched.

When the type of read/write request is sequential write, as describedabove, a control method is executed where the storage apparatus 4predicts necessary data to be collectively written from the cache memory9 to the hard disk drive 110, and thereby optimizes the process.

Further, when the type of read/write request is sequential write, acontrol method is executed where the storage apparatus 4 adjusts thestripe size according to the data transfer length.

When the type of read/write request is sequential write, a controlmethod is executed where the host system 2 changes the data transferlength based on the data length change program 23.

When the type of read/write request is sequential write, a controlmethod is executed where the data is preferentially destaged to the harddisk drive 110 according to the performance threshold value designatedby the user.

When the type of read/write request is random read, a control method isexecuted where the storage apparatus 4 reads into the cache memory 9data to be stored in the storage area of the hard disk drive 110 inwhich subsequent reading is predicted based on the access pattern.

When the type of read/write request is random read, a control method isexecuted where the storage apparatus 4 collectively stores, during itsspare time, data that is frequently read at a single location. Thiscontrol method includes the migration of the RAID level.

When the type of read/write request is random read, a control method isexecuted where the host system 2 changes the data transfer length basedon the data length change program 23, and optimizes the length andnumber of tags of the data length.

When the type of read/write request is random write, a control method isexecuted where the storage apparatus 4 collectively stores, at a singlelocation, data that is frequently overwritten and stored in differentstorage areas of the hard disk 110, or distributes the a plurality ofhard disk drives in order to increase the write speed. This controlmethod includes the migration of the RAID level.

When the type of read/write request is random write, a control method isexecuted where the storage apparatus 4 optimizes the stripe size.

When the type of read/write request is random write, a control method isexecuted where the host system 2 changes the data transfer length basedon the data length change program 23.

(4) Effect of First Embodiment

According to this embodiment, since the storage controller is ableanalyze the access pattern from a host system to a logical volume andperform optimal control for the relevant processing, it is possible toseek improvement in performance of the storage system even based on theparticularity of access patterns.

(5) Second Embodiment

The storage system according to the second embodiment is explainedbelow.

FIG. 21 shows the overall storage system 1′ according to the secondembodiment. The storage system 1′ is configured by a host system 2 beingconnected to a storage apparatus 4′ via a network 3, the storageapparatus 4′ being connected to a management terminal 12, and themanagement terminal 12 being connected to a support system 14 via anetwork 13.

The storage apparatus 4′ is a storage controller comprising a controller5′ for controlling the input and output of data to and from the hostsystem 2, and a hard disk drive unit 11 for storing data from the hostsystem 2.

The controller 5′ is configured by a host computer interface (indicatedas host computer I/F in the drawings) 60 for performing communicationcontrol with the host system 2, a processor 6′, a shared memory 7, acache memory 9, and a disk interface (indicated as disk I/F in thedrawings) 10′ for performing communication control with the hard diskdrive unit 11 being connected via a transfer control circuit 8′.

The processor 6′ refers to the various tables 91, 93, 94 stored in thecache memory 9 and executes the various programs 90, 92, 95, 96.

The transfer control circuit 8′ is a circuit for controlling the datatransfer among the host computer interface 60, the processor 6′, theshared memory 7, the cache memory 9 and the disk interface 10′.

Incidentally, the other constitutional elements are the same as thecorresponding constitutional element described above, and theexplanation thereof is omitted. Further, although only one controller 5′is indicated in this embodiment, a plurality of controllers 5′ may beprovided in the storage apparatus 4′.

Even with the foregoing configuration, since the storage controller isable analyze the access pattern from a host system to a logical volumeand perform optimal control for the relevant processing, it is possibleto seek improvement in performance of the storage system even based onthe particularity of access patterns.

(6) Other Embodiments

Although the plurality of host systems 2 or the plurality ofapplications A to C included in addition unit in the driver 21 foradding an identifier that identifies the respective host systems or therespective applications to the access information and sending suchidentifier, the addition unit may be configured as a separate hardwareconfiguration.

Although the storage apparatus (storage controller) 4 provided theanalysis unit for identifying the host system 2 or the applications A toC based on the identifier contained in the access information andanalyzing an access pattern of access information sent from theidentified host system or application; the management unit for managingthe identifier of the host system 2 or the applications A to C, theanalysis result of the access pattern analyzed with the analysis unit,and a control method for controlling the processing of data to be sentfrom a host system based on the analysis result or data to be stored ina logical volume; and the data processing controller for controlling theprocessing of data to be sent from a host system or data to be stored ina logical volume according to the control method managed by themanagement unit in the cache memory 9, the analysis unit, the managementunit and the data processing controller may also be provided as aseparate hardware configuration.

The present invention can be broadly applied to storage systems havingone or more storage controllers, or to various other storage systems.

1. A storage system including a plurality of host systems or a pluralityof applications for sending access information, and a storage controllerfor storing data in a logical volume provided in a storage area of aphysical disk; wherein said plurality of host systems or said pluralityof applications comprise an insertion unit for inserting an identifierthat identifies respective host systems or respective applications intosaid access information and sending said identifier; and wherein saidstorage controller comprises: an analysis unit for identifying a hostsystem or an application based on the identifier contained in saidaccess information and analyzing an access pattern of access informationsent from the identified host system or application; a management unitfor managing the identifier of said host system or said application, theanalysis result of the access pattern analyzed with said analysis unit,and a control method for controlling the processing of data to be sentfrom a host system based on said analysis result or data to be stored ina logical volume; and a data processing controller for controlling theprocessing of data to be sent from a host system or data to be stored ina logical volume according to the control method managed by saidmanagement unit.
 2. The storage system according to claim 1, whereinsaid data processing controller controls the processing of data to besent from a host system or data to be stored in a logical volume whenone among said plurality of host systems or said plurality ofapplications receives access information containing the identifier of ahost system managed with said management unit.
 3. The storage systemaccording to claim 1, wherein said data processing controller determinesthe method of controlling the processing of data to be sent from a hostsystem or data to be stored in a logical volume when said control methodis not being managed with said management unit; and wherein saidmanagement unit manages the control method determined by said dataprocessing controller.
 4. The storage system according to claim 1,wherein, when one among said plurality of host systems or said pluralityof applications receives access information not containing theidentifier of a host system managed with said management unit in saiddata processing controller, said analysis unit analyzes the accesspattern of said access information.
 5. The storage system according toclaim 1, wherein said identifier is a host computer identifier foridentifying said plurality of host systems or an application identifierfor identifying said plurality of applications.
 6. The storage systemaccording to claim 1, wherein said analysis unit determines the accessinformation of a sequential access or a random access, and analyzes theaccess pattern of the determined access information.
 7. The storagesystem according to claim 6, wherein said analysis unit analyzes atransfer length of data, a write start location for writing data in alogical volume, a storage order for storing data in a logical volume, oran access pattern of an access cycle to a logical volume.
 8. The storagesystem according to claim 7, wherein said storage controller creates alogical volume displaced in an amount that the write start location isdisplaced when there is displacement at the write start location forwriting data in said logical volume based on the analysis result of saidanalysis unit.
 9. A control method of a storage system including aplurality of host systems or a plurality of applications for sendingaccess information, and a storage controller for storing data in alogical volume provided in a storage area of a physical disk; whereinsaid plurality of host systems or said plurality of applicationscomprise an insertion step for inserting an identifier that identifiesrespective host systems or respective applications into said accessinformation and sending said identifier; and wherein said storagecontroller comprises: an analysis step for identifying a host system oran application based on the identifier contained in said accessinformation and analyzing an access pattern of access information sentfrom the identified host system or application; a management step formanaging the identifier of said host system or said application, theanalysis result of the access pattern analyzed with said analysis unit,and a control method for controlling the processing of data to be sentfrom a host system based on said analysis result or data to be stored ina logical volume; and a data processing control step for controlling theprocessing of data to be sent from a host system or data to be stored ina logical volume according to the control method managed at saidmanagement step.
 10. The control method of a storage system according toclaim 9, wherein at said data processing control step, the processing ofdata to be sent from a host system or data to be stored in a logicalvolume is controlled when one among said plurality of host systems orsaid plurality of applications receives access information containingthe identifier of a host system managed with said management unit. 11.The control method of a storage system according to claim 9, wherein atsaid data processing control step, the method of controlling theprocessing of data to be sent from a host system or data to be stored ina logical volume is determined when said control method is not beingmanaged at said management step; and wherein at said management unitstep, the control method-determined at said data processing control stepis managed.
 12. The control method of a storage system according toclaim 9, wherein, at said data processing control step, when one amongsaid plurality of host systems receives access information notcontaining the identifier of a host system managed at said managementstep, the access pattern of said access information is analyzed at saidanalysis step.
 13. The control method of a storage system according toclaim 9, wherein said identifier is a host computer identifier foridentifying said plurality of host systems or an application identifierfor identifying said plurality of applications.
 14. The control methodof a storage system according to claim 9, wherein at said analysis step,the access information of a sequential access or a random access isdetermined, and the access pattern of the determined access informationis analyzed.
 15. The control method of a storage system according toclaim 14, wherein at said analysis step, a transfer length of data, awrite start location for writing data in a logical volume, a storageorder for storing data in a logical volume, or an access pattern of anaccess cycle to a logical volume is analyzed.
 16. The control method ofa storage system according to claim 15, wherein said storage controllerfurther comprises a step for creating a logical volume displaced in anamount that the write start location is displaced when there isdisplacement at the write start location for writing data in saidlogical volume based on the analysis result at said analysis step.